You can either buy another one of those potions (i.e. burn salve fortitude tonic) or you can use GG's cleansing boon. Other than that they are unremovable, so I suggest you just try to avoid them completely.
I always just save those enemies till I am a higher level and then one shot them without incurring weakening or corrosion as they are very bad. (weakening especially)
I speak chaos.